Pressure responsive actuator



April 11,1950 1 .R. w. PHELPS 2,503,594

PRESSURE RESPONSIVE ACTUATOR Filed Dec. 31, 1 946 4 v INVEHTOR.

5 J7 R.w. nzzpj ATT'YS Patented Apr. 11, 19 50 PRESSURE RESPONSIVE ACTUATOR Ross W. Phelps, Orilla, Ontario, Canada Application. December 31, 19.46; Serial No.

In Canada. October 17,1946

2 Claims.

This invention relates to a pressure responsive actuator adaptable for use in measuring. fluid pressures in storage tanks and the like.

In the field of pressure actuators generally where the same are mounted on a fluid pressure tank much difliculty has been encountered with a. chattering of the element actuated thereby such as a switch element due to pulsations of the pressure pump. Further, due to the high pressures encountered, the actuated element employed usually lacks a sufficient' seal and thus moisture sometimes creeps into the mechanism thereof destroying its operation. Heretofore, such. devices have not been capable of being actuated at a predetermined pressure with a great accuracy:. This is due not only to the nature of the construction and design adopted but also to the fact that the actuator is normally disposed in the column of fluid flow or pressure in the tank, thus being susceptible to surges of pressure derivedfrom the pump.

It is, therefore, the main object of the present invention to provide a pressure actuator for a device such as a switch for hydraulic devices which employs conventional electrical switch means actuated by a pressure diaphragm which is substantially insulated but in communication with the body of fluid under pressure in a pressure tank.

Another object ofthe present invention. is to provide a pressure actuator of this type which is disposed in a chamber communicating by a small duct with the main body of fluid under pressure in a tank, whereby the restricting action of said duct dampens pressure surge passing to said actuator but nevertheless communicates the mean pressure to provide actuation of the same.

A further object of the present invention is to provide a pressure actuator as formerly described which embodies a minimum of operable elements thereby being adapted to mass production means and marketable at low cost.

With these and other objects in view, the present invention generally comprises a device for actuating control mechanisms in response to changes in the fluid pressure. The device includes a pressure chamber adjacent a small communicating passage connecting the same to a main pressure vessel. A communicating passage is sufficiently small to ensure dampening to pressure pulsations from one chamber to the other. The said mechanism is operated by means in the pressure chamber which are re sponsive to changes in pressure, said means being tion. I8 01 the switch in the form of a diaphragm structure which serves a double function of sealing the said mechanism and actingv as an actuating element in the same.

Other objects of the present invention will be, revealed by a study of the following specification taken in conjunction with the accompanyingd'rawings.

In the drawings:

Fig. 1 is a sectional view of a portion of a. pressure tank showing the present invention mounted in the casing.

Fig. 2 is a plan view of. the curved washer which is used in the present invention.

Fig. 3 is the curved washer shown in. perspective inorder that the nature of the curve can, easily beseen.

Fig. 4 is a plan view of the pressure disc used in the present invention.

Fig. 5 is a plan view of the ring member used inthe present invention.

Referring to the drawings, a fluid pressure tank has a casing in carrying a body of fluid H under pressure. A threaded counter bore I2 is cut in the casing as shown extending to form a chamber l3 in its lower terminus. A communieating duct l4 extends from chamber body of fluid H in the tank 10 and a conventional electrical switch means l5 having a plunger I6 is mounted in the threaded counter borev l2 by a housing H.

In. this instance the housing is preferably cast of phenol formaldehyde thermosetting resin and designed to enclose the threaded mounting por- IS. The housing I! is partially cut away as indicated at l9 and 20 to accommodate a wrench or other suitable tool whereby the housing l1 may be fastened tightly into the threaded counter bore l2 by its mating threads 2! When the housing I 1 is introduced into the bore [2 it thereby encases and holds the operative elements of the actuating means employed according to the present invention. As will be observed, a resilient curved washer 22 preferably formed of spring steel fits over the plunger I6 of the switch I 5 by its orifice 22a and terminates outwardly thereof in flanges 22b. A pressure disc or pad 23 is mounted slidably within the housing walls Ila on the flanges 22b of the curbed washer 22 to engage the plunger l6 of the switch [5.

The curved washer means 22 is designed to develop a predetermined pressure. In the present instance, therefore, the washer governs the presl3 to the sure at which the switch IE will be actuated and it has been found that a resilient member of this type will develop a greater pressure than a coiled spring or other similar means. Further, it will be observed that the curved washer holds the pressure disc substantially at right angles to the axis of the plunger l6 by its flanges 22b holding it steady at all times from oscillatory movement outside of its right axial plane.

It is particularly important in all pressure devices that leakage of pressure be avoided thus normally necessitating the use of sealing compounds, gasket devices, and the like. In the present instance, however, it will be observed that an annular ring member 24, preferably of metal, is disposed in the lower terminus of the housing ll and is designed slidably to enclose the periphery of the disc 23 and firmly to engage a rubber sealing disc 25, the latter extending the complete diameter of the bore l2 substantially as revealed in Figure 1. Corresponding to the ring 24, an annular shoulder 26 is provided onto which the sealing disc 25 may be firmly pressed by tightening the housing IT. The sealing disc 25 thus holds the pressure disc 23 against the curved resilient washer 22 and prevents any communication of fluid from the chamber l3 into the interior of the housing I! in the area of the plunger l6. In this way, a leakage of pressure is guarded against through the switch I! itself and further it will be noted that the edges of the sealing disc 25 are so engaged on the shoulders 26 that escape of pressure through mating parts in that area is also guarded against.

It has been found that the diameter of the communicating duct 14 is a factor which contributes substantially to the dampening of oscillatory pressures normally brought about by pulsations of the pump means (not shown). As the pressure increases in the chamber IS, the rubber sealing disc is depressed causing the pressure disc to actuate the plunger l6 and thereby actuate the electrical switch means I to shut the pump (not shown) off.

I have thus provided a pressure switch which, due to the mounting means employed, does not restrict the pressure flow. The present device does not chatter and it definitely does react to pressure without vibration and a chattering action. As will be observed the means employed are a minimum and feature great simplicity in design and construction resulting in a highly eflicient switch unit both from the manufacturers and the users point of view.

What I claim as my invention is:

1. A pressure operated device for operating a 4 mechanism operating plunger comprising a diaphragm, means for mounting said diaphragm in a fluid pressure chamber so that a fluid pressure can be caused to act on one side thereof, a resilient curved washer having a predetermined resiliency, means for mounting said washer to cause it to exert pressure on the opposite face of said diaphragm to said fluid in said fluid chamber, said resilient Washer being orificed to cause a mechanism operating plunger to operatively engage with said diaphragm, said diaphragm being adapted to respond in predetermined manner to fluid pressure changes within said fluid pressure chamber, a flat pressure pad with one side thereof engaging one side of said diaphragm, said resilient Washer and the mechanism operating plunger engaging with said pressure pad on its other side.

2. A pressure operating device for operating a mechanism operating plunger comprising a housing adapted to thread into a fluid pressure chamber, said fluid pressure chamber being formed with a shoulder and said housing being adapted to tighten towards said shoulder, a diaphragm adapted to be securely retained between said shoulder and said housing to cause a fluid pressure to act on one side thereof, a resilient curved washer adapted to seat within said housing and to exert a pressure on the opposite face of said diaphragm to said fluid in said fluid chamber, said housing and washer being orificed to cause a mechanism operating plunger to oper-. atively engage with said diaphragm, said diaphragm being adapted to respond in predetermined manner to fluid pressure changes within said fluid pressure chamber, a flat pressure pad with one side thereof engaging one side of said diaphragm, said resilient washer and the mecha-' nism operating plunger engaging with said pressure pad on its other side.

ROSS W. PHELPS.

REFERENCES CITED The following references are of record in the 

